Yeah but one other thing to consider is just how technically advanced having a duress password is for the average joe. I think about it like this. Say you're a CBP border agent on the US/Canada border. You inspect peoples phones for images of contraband, etc upon entry. You probably inspect ~150-200 phones per day, now say among the sea of people that are coming through, one of the people's whose phone you searched was actually in "duress mode" and was hiding the real data on the phone. You can't tell me an officer is going to pick that out unless it's something really obvious.

I would go as so far as to say that most border agent's that search phones are probably not even aware that this is a thing that people do. Sure they might have gotten training in a classroom for it, but as far as real world experience goes, maybe 1 out of every 5000 people has a setup like this.